Adiabatic topological pumping in a semiconductor nanowire

Abstract

The adiabatic topological pumping is proposed by periodically modulating a semiconductor nanowire double-quantum-dot chain. We demonstrate that the quantized charge transport can be achieved by a nontrivial modulation of the quantum-dot well and barrier potentials. When the quantum-dot well potential is replaced by a time-dependent staggered magnetic field, the topological spin pumping can be realized by periodically modulating the barrier potentials and magnetic field. We also demonstrate that in the presence of Rashba spin–orbit interaction, the double-quantum-dot chain can be used to implement the topological spin pumping. However, the pumped spin in this case can have a quantization axis other than the applied magnetic field direction. Moreover, we show that all the adiabatic topological pumping are manifested by the presence of gapless edge states traversing the bandgap as a function of time.

Control of dimer chain topology by Rashba-Dresselhaus spin-orbit coupling

“…Together with TE-TM SOC, effective Zeeman field and in-plane potential (lattices), RDSOC plays the role of a supplementary control knob for implementing effective Hamiltonians of interest and for controlling the mode topology [57]. The crucial property offered by LC microcavities [58][59][60][61][62] is the tunability of the modes by means of the external voltage applied to the LC molecules. This allows to switch the RDSOC on and off electrically.…”

“…This allows to switch the RDSOC on and off electrically. So far, the effect of the RDSOC (which in 1D is equivalent to the Rashba SOC) in the SSH setting has been theoretically discussed in the context of electronic systems [58][59][60][61][62], but only for a homogeneous or small Rashba SOC giving no topological effects.…”